Interest Rises in Studies of Atomic Shells

By KEITH SCHNEIDER, Special to The New York Times

Published: May 28, 1990

WASHINGTON, May 27—
The disclosure of a flaw in the design of nuclear artillery shells deployed in Europe has generated new interest in a number of Government studies that said 14 types of nuclear weapons had been temporarily withdrawn from the American arsenal since 1961 for repairs.

In three instances, the studies say, the repairs corrected problems with powerful chemical explosives that might have led to accidental non-nuclear detonations. Such explosions could disintegrate the plutonium triggers of nuclear warheads, dispersing highly radioactive and potentially lethal particles into the environment.

The studies were conducted for the Energy Department from 1983 to 1987 by independent researchers, top administrators and scientists at the Lawrence Livermore National Laboratory in Livermore, Calif. They were made public starting in the mid-1980's during Congressional debate on a treaty to limit underground nuclear tests in the United States and the Soviet Union.

Vulnerable, but No Blast

Energy Department engineers said Thursday that an American nuclear weapon had never detonated accidentally, causing a spontaneous atomic explosion. Twice in the 60's, chemical explosives in nuclear warheads ignited after B-52 bombers crashed in Spain and Greenland, but no civilians were injured by radiation.

In the hearings before the Senate Armed Services Committee, the directors of three nuclear weapons laboratories urged the Pentagon to withdraw the or short-range attack missile, or SRAM-A, from bombers taking part in a 24-hour alert. The missile, with a W-69 warhead, is vulnerable to accidental detonation, but will not cause a nuclear explosion in the event of severe stress like a fire or a crash, the laboratory directors said.

Defense Secretary Dick Cheney met with the directors of the Los Alamos, Lawrence Livermore and Sandia National Laboratories on Saturday to consider taking the weapons out of operation. ''They had a very good discussion,'' said Tom Olson, a spokesman for the department, ''but they reached no decision.''

Problems With Achieving Safety

The Pentagon had said previously that it would not take any action until it looked into the safety of the missiles. A Defense Department spokeswoman, Jan Bodanyi, said most of what was discussed at the session was classified. Energy Secretary James Watkins and Gen. Colin L. Powell, Chairman of the Joint Chiefs of Staff, were on hand.

But the disclosure last week that 300 to 400 nuclear artillery shells were returned from Europe in 1989 for repair of defects that could have caused them to go off accidentally underscored the Energy Department's difficulties in designing safe weapons.

The disclosure also widened the concern about management and safety problems in the Energy Department's nuclear weapons industry, scattered through 12 states, to include the hazards to military personnel and civilians from accidental detonations.

Revelations of Flaws

''A prominent issue in all this is that there are 22 types of warheads in the United States arsenal today,'' said William M. Arkin, director of nuclear research in Washington for the international environmental group Greenpeace.

''Seven of those have had serious manufacturing or design flaws. It reveals that what the Energy Department is manufacturing is as flawed as the nuclear weapons complex itself.''

A spokesman for the Department of Energy, Thomas C. Olson, declined to respond to Mr. Arkin's criticism. But he said: ''Part of having nuclear weapons is the responsiblity to look hard to find any possible safety flaw in the weapon. That review has been part of the system since the 1950's. We take that very seriously.''

The first weapon recalled from the arsenal, according to a 1983 study for the Energy Department, was the W-47 warhead for the Polaris missile. During routine surveillance of the arsenal in 1961, engineers for the Atomic Energy Commission found that the nuclear materials in the warhead had suffered enough radioactive decay to diminish the warhead's power. Tests in Nevada confirmed the problem. Some weapons were repaired.

Two years later, problems were discovered in the same warhead's safety systems. Studies indicated that its chemical explosive could detonate and possibly start a nuclear chain reaction if it were dropped or struck hard in a vulnerable spot. The A.E.C. designed a new type of W-47 and by 1967 had placed it on all Polaris missiles, the report said.

A Warhead Problem

Another design flaw was discovered in the W-68 warhead, produced from 1970 to 1975 for Poseidon missiles. During their evaluation testing of the warheads in the mid-1970's, Livermore scientists discovered that the chemical explosives had degraded and were emitting an odor. Residues from the explosive had reacted chemically with adhesives in the warheads' detonators, and scientists feared the detonator would fail. The problem was solved in 1979 by rebuilding the thousands of W-68's.

The deadly power of the chemical explosives in atomic weapons was illustrated in 1959 at the Los Alamos National Laboratory in New Mexico. Six people were killed in two separate accidents while testing a chemical explosive to be used on the Army's Sergeant surface-to-air missile, which has since been retired. A report in October 1987 by Livermore scientists said the accidents led designers to exchange the chemical explosive for one less liable to accidental detonation.

The design flaws in the W-79 nuclear artillery shell that were disclosed last week focused on the warhead's inability to withstand severe stress like a powerful blast or rifle shot to a vulnerable spot. The shells were returned last year to the Pantex plant near Amarillo, Tex., where steel plates were welded to the shell's interior walls. The repairs have been completed or are close to being completed, Energy Department engineers say.

''It's not surprising that the safety problems have appeared in nuclear weapons, given the Department of Energy's track record on safety in other areas,'' said David Albright, a physicist at the Federation of American Scientists, a Washington-based arms control group.